This Body Fat calculator estimates your total body fat percentage using precise measurements. For the International System of Units (SI), select the “Metric Units” tab. For accuracy, measure to the nearest ¼ inch (0.5 cm). The calculator applies the U.S. Navy method and provides an estimate based on the BMI method—both are detailed below.

Body Fat Reference Guide

1. ACE Body Fat Categories

For Men (18+):

Essential: <6%

Athlete: 6-13%

Fitness: 14-17% (18-39) | 14-19% (40+)

Acceptable: 18-24% (18-39) | 20-25% (40+)

Obese: ≥25% (18-39) | ≥26% (40+)

For Women (18+):

Essential: <10%

Athlete: 10-20%

Fitness: 21-24%

Acceptable: 25-31%

Obese: ≥32%

Based on American Council on Exercise (ACE) standards

Ideal Body Fat Percentages

Jackson & Pollock Recommendations:

Age	Men	Women
18-25	8%	21%
26-35	10%	22%
36-45	12%	23%
46-55	14%	24%
56+	16%	25%

Key Body Fat Concepts

Essential Fat

Minimum required for physiological functions (hormones, organ protection).

Storage Fat

Excess fat is linked to health risks when above ideal ranges.

Fat Distribution

Men tend to store fat abdominally; women in hips/thighs (patterns may shift with age).

Measurement Methods in This Calculator

A. U.S. Navy Method

• Measures neck/waist (plus hips for women)
• Equations account for height and gender
• Accuracy: ±3-5% for most adults

B. BMI Method

Estimates fat percentage using:

Men: (1.20 × BMI) + (0.23 × Age) – 16.2
Women: (1.20 × BMI) + (0.23 × Age) – 5.4

Best for population studies (less precise for individuals)

Note: For clinical purposes, consider DEXA scans or hydrostatic weighing. Always consult a healthcare provider before making significant body composition changes.